Nicole Richie is a big Britney Spears fan, which would explain how she found herself chained up on a dog leash and walking on all fours at the pop star’s “Piece of Me” show in Las Vegas.

The act was all for Britney’s performance of “Freakshow.” Afterward, Spears tweeted, "Can we all give a round of applause to @NicoleRichie for playing along in the show tonight? U looked hot crawling on all fours.”